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Abstract:

A hook pose detecting equipment and a crane with the hook pose detecting
equipment, in which the hook pose detecting equipment comprises an angle
measuring apparatus for obtaining the angle between an axis in a second
coordinate system and the corresponding axis in a first coordinate
system, an acceleration measuring meter for obtaining the acceleration of
the hook in a predetermined direction, a processor for building the first
coordinate system and the second coordinate system, and an output
equipment. The first coordinate system is relatively fixed with a
predetermined location, and the second coordinate system is relatively
fixed with the hook. The processor obtains the pose parameters of the
hook in the first coordinate system according to the angle obtained by
the angle measuring apparatus and the acceleration obtained by the
acceleration measuring meter. The operator is able to take appropriate
hook-stabilizing measures according to the pose parameters, and thus the
efficiency of lifting work is increased.

Claims:

1. A hook attitude detecting device, comprising: an angle measuring
instrument configured to obtain an angle between a coordinate axis of a
second coordinate system and a corresponding coordinate axis of a first
coordinate system in real time; an acceleration measuring meter
configured to obtain an acceleration of a hook in a predetermined
direction in real time, there being a predetermined angle between the
predetermined direction and the coordinate axis of the second coordinate
system; a processor configured to establish the first coordinate system
and the second coordinate system, wherein the first coordinate system is
fixed relative to a predetermined position and the second coordinate
system is fixed relative to the hook, the coordinate axis of the first
coordinate system corresponds to the coordinate axis of the second
coordinate system; and attitude parameters of the hook in the first
coordinate system are obtained from the angle obtained by the angle
measuring instrument and the acceleration obtained by the acceleration
measuring meter; and an output device configured to output the attitude
parameters.

2. The hook attitude detecting device according to claim 1, wherein the
first coordinate system is a rectangular coordinate system comprising a
X1 axis, a Y1 axis and a Z1 axis, and the second coordinate system is a
rectangular coordinate system comprising a X2 axis, a Y2 axis and a Z2
axis, with the X1 axis, the Y1 axis and the Z1 axis respectively
corresponding to the X2 axis, the Y2 axis and the Z2 axis.

3. The hook attitude detecting device according to claim 2, wherein the
angle measuring instrument is a triaxial angle measuring instrument, and
there are predetermined angles between axes of three measuring shafts of
the triaxial angle measuring instrument and the three coordinate axes of
the second coordinate system, respectively.

4. The hook attitude detecting device according to claim 3, wherein the
predetermined angles between the axes of the three measuring shafts of
the angle measuring instrument and the three coordinate axes of the
second coordinate system are all equal to zero degree.

5. The hook attitude detecting device according to claim 2, wherein the
acceleration measuring meter is a triaxial acceleration measuring meter,
and there are predetermined angles between axes of three measuring shafts
of the triaxial acceleration measuring meter and the three coordinate
axes of the second coordinate system, respectively.

6. The hook attitude detecting device according to claim 5, wherein the
predetermined angles between the axes of the three measuring shafts of
the acceleration measuring meter and the three coordinate axes of the
second coordinate system are all equal to zero degree.

7. The hook attitude detecting device according to claim 1, wherein the
output device comprises a display device which displays the attitude
parameters in a form of a schematic diagram.

8. The hook attitude detecting device according to claim 1, wherein the
attitude parameters comprise at least one of instantaneous speed,
movement direction and position of the hook in the first coordinate
system.

9. The hook attitude detecting device according to claim 1, wherein the
processor can further compare the attitude parameters with predetermined
threshold values of the parameters so as to determine the security of a
hoisting operation, and can perform a predetermined processing according
to a comparison result.

10. A crane, comprising a lifting arm, a hanging wire rope, a hook and
the hook attitude detecting device according to claim 1, wherein the
hanging wire rope has a lower end connected with the hook and an upper
end connected with a fixed pulley on the lifting arm, the angle measuring
instrument and the acceleration measuring meter of the hook attitude
detecting device are both fixed to the hanging wire rope or to the hook.

11. The crane according to claim 10, wherein the first coordinate system
is a rectangular coordinate system comprising a X1 axis, a Y1 axis and a
Z1 axis, and the second coordinate system is a rectangular coordinate
system comprising a X2 axis, a Y2 axis and a Z2 axis, with the X1 axis,
the Y1 axis and the Z1 axis respectively corresponding to the X2 axis,
the Y2 axis and the Z2 axis.

12. The crane according to claim 11, wherein the angle measuring
instrument is a triaxial angle measuring instrument, and there are
predetermined angles between axes of three measuring shafts of the
triaxial angle measuring instrument and the three coordinate axes of the
second coordinate system, respectively.

13. The crane according to claim 12, wherein the predetermined angles
between the axes of the three measuring shafts of the angle measuring
instrument and the three coordinate axes of the second coordinate system
are all equal to zero degree.

14. The crane according to claim 11, wherein the acceleration measuring
meter is a triaxial acceleration measuring meter, and there are
predetermined angles between axes of three measuring shafts of the
triaxial acceleration measuring meter and the three coordinate axes of
the second coordinate system, respectively.

15. The crane according to claim 14, wherein the predetermined angles
between the axes of the three measuring shafts of the acceleration
measuring meter and the three coordinate axes of the second coordinate
system are all equal to zero degree.

16. The crane according to claim 10, wherein the output device comprises
a display device which displays the attitude parameters in a form of a
schematic diagram.

17. The crane according to claim 10, wherein the attitude parameters
comprise at least one of instantaneous speed, movement direction and
position of the hook in the first coordinate system.

18. The crane according to claim 10, wherein the processor can further
compare the attitude parameters with predetermined threshold values of
the parameters so as to determine the security of a hoisting operation,
and can perform a predetermined processing according to a comparison
result.

Description:

[0001] This application claims the priority of Chinese Patent Application
No. 200910226102.4, entitled "HOOK POSE DETECTING EQUIPMENT AND CRANE"
filed on Nov. 20, 2009 with State Intellectual Property Office of PRC,
which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The present invention relates to a crane control technique, and in
particular to a hook attitude detecting device and a crane including this
hook attitude detecting device.

BACKGROUND OF THE INVENTION

[0003] Cranes are widely applied as lifting and conveying equipments in
construction industry, manufacturing industry, and port transportation
industry. There are various kinds of cranes, each kind of which is of a
different structure. For a truck crane, it includes a chassis, a slewing
mechanism, a lifting arm, a hook and a hoisting mechanism. The lifting
arm has a lower part connected with the chassis by the slewing mechanism
and an upper part on which the hook is hung by a wire rope wound around a
pulley block to be connected to the hoisting mechanism. In the hoisting
mechanism, the hook is driven by the wire rope to make movements such as
rising, stop and lowering; while the lifting arm may rotate about a
vertical axis under the driving of the slewing mechanism, so as to move
the hook in a horizontal plane.

[0004] In the hoisting operation of a crane, there are many steps to be
performed, which generally include lowering a hook, hoisting, laterally
moving and subsequently lowering the hook, etc. In lowering of the hook,
a hoisting drum of the hoisting mechanism rotates in one direction, and
the hook brings the wire rope to move downwardly under gravity, till the
hook reaches a suitable position above the goods to be hoisted, and then
the hook is fixed to the goods to be hoisted. In hoisting, the hoisting
drum of the hoisting mechanism rotates in an opposite direction, and the
hook and the goods are moved together upwardly by the pulling of the wire
rope, thus the goods goes away from the ground. After the goods has been
moved away from the ground, the slewing mechanism is operated and the
step of the laterally moving begins. The lifting arm laterally rotates,
and the hook laterally moves together with the goods, so as to allow the
goods to arrive above a predetermined position. In subsequently lowering
of the hook, the hoisting drum rotates reversely again after the goods
arrives above the predetermined position, and the goods and the hook
moves downwardly, so as to allow the goods to reach the predetermined
position, thereby performing the transposition of the goods. In hoisting,
the hook moves not only in a vertical direction but also in a lateral
direction. Due to inertia and an external force, the hook hung on the
upper part of the lifting arm by a wire rope and the goods may sway
accordingly, in particular when the hook carrying the goods begins to
move laterally or stops laterally moving after the goods reaches the
predetermined position, the swaying amplitude of the hook and the goods
may be increased.

[0005] The swaying of the hook may affect the efficiency of the hoisting
operation of the crane. When the hook is lowered, in order to keep the
hook stable relative to the goods and avoid the collision between the
hook and the goods, it is necessary to wait for a suitable period of
time, until the hook stops swaying. In the laterally moving of the
hoisted goods, in order to avoid the collision caused by swaying of the
goods, it is also necessary to move the hook and the goods at a
relatively low speed. After the hoisted goods reaches the predetermined
position, in order to accurately place the goods onto the predetermined
position, it is also necessary to lower the hook after the goods stops
swaying. Currently, in the filed of crane, there is a common problem that
the hoisting time is prolonged due to the swaying of the hook, which
reduces the hoisting efficiency of the crane.

[0006] The above-mentioned problems occur not only in the hoisting
operation of a truck crane, but also in the hoisting operation of a
gantry crane or other types of cranes.

[0007] In view of the above-mentioned problems, the swaying amplitude of
the hook is currently reduced by taking a anti-swaying hook-stabilizing
measures, so as to more quickly stop the swaying of the hook and thus to
reduce the adverse effects of swaying hook on the efficiency of the
hoisting operation. In the anti-swaying hook-stabilizing measures, a
control device is generally used to move the hook at a suitable frequency
and amplitude in the direction opposite to the swaying direction, based
on the swaying amplitude, frequency and direction of the hook, so as to
stop the hook in a shorter time. Presently, the anti-swaying
hook-stabilizing measures substantially depend on the appropriate control
on the hook by experienced operator.

[0008] In order to reduce the dependence on the operating experience of
the operator, the European patent document EP1757554 disclosed an
anti-swaying control technique for a crane. In the technical solution
disclosed in this patent document, attitude parameters of a hook or goods
are predetermined in a preset mode, and a control system takes a proper
anti-swaying measures according to the predetermined attitude parameters
to reduce the adverse effects of swaying on the hoisting operation. One
principle of this technical solution is that the movement situation of a
hook, i.e., attitude parameters of the hook, in hoisting operation is
predetermined; and a control strategy is determined according to the
predetermined attitude parameters of the hook to allow the hook move in a
predetermined way, so as to reduce the swaying amplitude of the hook and
thus to stop the hook more quickly, thereby reducing the adverse effects
of the swaying hook on the efficiency of the hoisting operation. However,
due to the complexity of the actual hoisting operation, it is difficult
for the predetermined attitude parameters of the hook to be identical
with the actual attitude parameters, thus this technical solution is only
applicable in a stable hoisting operation environment. When a hoisting
operation is performed in an operation environment where the attitude
parameters of a hook are not predetermined, the above technical solution
will not increase the efficiency of the hoisting operation of the crane.

[0009] In a hoisting operation, one technical difficulty in the crane
field is to determine the actual attitude parameters of a hook and
provide a basis for controlling the movement of the hook so as to
increase the efficiency of the hoisting operation of a crane.

SUMMARY OF THE INVENTION

[0010] In view of the above-mentioned technical difficulty, a first object
of the present invention is to provide a hook attitude detecting device,
for determining actual attitude parameters of a hook and providing a
basis for controlling the movement of the hook.

[0011] A second object of the present invention is to provide a crane with
the above-mentioned hook attitude detecting device, in which the movement
state of a hook is known according to actual attitude parameters of the
hook and hook-stabilizing measures may be taken to increase the
efficiency of the hoisting operation of the crane.

[0012] To achieve the first object mentioned above, a hook attitude
detecting device according to the present invention includes:

[0013] an angle measuring instrument configured to obtain an angle between
a coordinate axis of a second coordinate system and a corresponding
coordinate axis of a first coordinate system in real time;

[0014] an acceleration measuring meter configured to obtain an
acceleration of a hook in a predetermined direction in real time, there
being a predetermined angle between the predetermined direction and the
coordinate axis of the second coordinate system;

[0015] a processor configured to establish the first coordinate system and
the second coordinate system, wherein the first coordinate system is
fixed relative to a predetermined position and the second coordinate
system is fixed relative to the hook, the coordinate axis of the first
coordinate system corresponds to the coordinate axis of the second
coordinate system; and attitude parameters of the hook in the first
coordinate system may be obtained from the angle obtained by the angle
measuring instrument and the acceleration obtained by the acceleration
measuring meter; and

[0016] an output device configured to output the attitude parameters.

[0017] Preferably, the first coordinate system is a rectangular coordinate
system including a X1 axis, a Y1 axis and a Z1 axis, and the second
coordinate system is a rectangular coordinate system including a X2 axis,
a Y2 axis and a Z2 axis, with the X1 axis, the Y1 axis and the Z1 axis
respectively corresponding to the X2 axis, the Y2 axis and the Z2 axis.

[0018] Preferably, the angle measuring instrument is a triaxial angle
measuring instrument, and there are predetermined angles between axes of
three measuring shafts of the triaxial angle measuring instrument and the
three coordinate axes of the second coordinate system, respectively.

[0019] Preferably, the predetermined angles between the axes of the three
measuring shafts of the triaxial angle measuring instrument and the three
coordinate axes of the second coordinate system are all equal to zero
degree.

[0020] Preferably, the acceleration measuring meter is a triaxial
acceleration measuring meter, and there are predetermined angles between
axes of three measuring shafts of the triaxial acceleration measuring
meter and the three coordinate axes of the second coordinate system,
respectively.

[0021] Preferably, the predetermined angles between the axes of the three
measuring shafts of the acceleration measuring meter and the three
coordinate axes of the second coordinate system are all equal to zero
degree.

[0022] Preferably, the output device includes a display device which
displays the attitude parameters in a form of a schematic diagram.

[0023] Preferably, the attitude parameters include at least one of
instantaneous speed, movement direction and position of the hook in the
first coordinate system.

[0024] Preferably, the processor can further compare the attitude
parameters with predetermined threshold values of the parameters so as to
determine the security of a hoisting operation, and can perform a
predetermined processing according to a comparison result.

[0025] To achieve the second object mentioned above, a crane according to
the present invention includes a body of the crane, a hanging wire rope
and a hook, wherein the hanging wire rope has a lower end connected with
the hook and an upper end connected with a fixed pulley on body of the
crane, and differs from the prior art in further including any hook
attitude detecting device mentioned above, wherein the angle measuring
instrument and the acceleration measuring meter of the hook attitude
detecting device are both fixed to the hanging wire rope or to the hook.

[0026] In the hook attitude detecting device according to the present
invention, the processor establishes the first coordinate system and the
second coordinate system in space, and obtains attitude parameters of the
hook based on these two coordinate systems to know the movement state of
the hook. The first coordinate system is fixed relative to a
predetermined position which may be fixed relative to related parts of
the crane, and the second coordinate system is associated with the
movement of the hook, such that the movement state of the hook may be
reflected by the relative movement state between these two coordinate
systems. The angle measuring instrument is utilized to obtain the angle
between the coordinate axis of the second coordinate system and the
corresponding coordinate axis of the first coordinate system. The
acceleration measuring meter is utilized to obtain the acceleration of
the hook in the predetermined direction fixed relative to the second
coordinate system and being at the predetermined angle relative to the
coordinate axis of the second coordinate system so as to provide a basis
for obtaining the acceleration of the hook in the direction of each
coordinate axis of the second coordinate system. The processor also can
obtain accelerations of the hook in the respective coordinate axes of the
first coordinate system according to the acceleration obtained by the
acceleration measuring meter and the angle obtained by the angle
measuring instrument; and can obtain the attitude parameters of the hook
according to the accelerations of the hook in the respective coordinate
axes of the first coordinate system, so as to determine the movement
state of the hook. Then, the attitude parameters obtained by the
processor may be output by an output device in a suitable manner. The
above-mentioned hook attitude detecting device according to the present
invention may provide attitude parameters of a hook, thus a control
system of a crane or an operator may accurately know information such as
position, operating speed and swaying amplitude of the hook from the
attitude parameters output by an output device so as to determine the
movement state of the hook, and then take suitable hook-stabilizing
measures according to the movement state of the hook, so as to reduce the
time required for the hoisting operation and improve the efficiency of
the hoisting operation.

[0027] In a further technical solution, the first coordinate system and
the second coordinate system both are rectangular coordinate systems
including three coordinate axes. In such a technical solution, more
attitude parameters of a hook can be obtained by the three coordinate
axes. Further, a control system of a crane or an operator can more
accurately determine information of the hook in a three-dimensional space
and take hook-stabilizing measures better.

[0028] In a further technical solution, the angles between the
corresponding coordinate axes of the two coordinate systems are obtained
by the triaxial angle measuring instrument. In this way, on the one hand,
the measuring accuracy can be increased, and on the other hand, the data
of the angles can be obtained more quickly, thereby improving the
responding speed of the hook attitude detecting device. In a preferred
technical solution, the axes of the three measuring shafts of the
triaxial angle measuring instrument are respectively parallel to the
three coordinate axes of the second coordinate system, which can reduce
the processing steps of the angle measuring instrument and improve the
processing speed of the angle measuring instrument.

[0029] Similarly, in a further technical solution, the acceleration of a
hook in each direction is obtained by the triaxial acceleration measuring
meter, which can improve the measuring accuracy and the responding speed
of the hook attitude detecting device. In a preferred technical solution,
the axes of the three measuring shafts of the triaxial acceleration
measuring meter are respectively parallel to the three coordinate axes of
the second coordinate system, which can reduce the processing steps of
the acceleration measuring meter and improve the processing speed of the
acceleration measuring meter.

[0030] In a further technical solution, the output device includes the
display device by which the attitude parameters of the hook may be
illustrated in a form of a schematic diagram. This technical solution can
provide visualized operating information for an operator, such that the
operator may take hook-stabilizing measures better to facilitate
improving the efficiency of the hoisting operation.

[0031] In a further technical solution, the processor may compare the
obtained attitude parameters of the hook with predetermined threshold
values of the parameters, and judge according to the predetermined
strategy whether the position and the speed of the hook is out of the
predetermined range or not; and then determine whether to perform related
processing or not according to the judgment result; and output a
predetermined indication to further remind the operator if it is
necessary to perform the predetermined processing. By means of this
technical solution, the efficiency of the hoisting operation is improved
while the safety accidents are reduced or avoided.

[0032] Based on the above-mentioned hook attitude detecting device, the
present invention further provides a crane including the above-mentioned
hook attitude detecting device. Since the hook attitude detecting device
has the above-mentioned technical effects, the crane including the
above-mentioned hook attitude detecting device also has corresponding
technical effects.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] FIG. 1 is a general structural schematic view of a truck crane;

[0034]FIG. 2 is a structural block diagram of a hook attitude detecting
device according to a first embodiment of the present invention;

[0035]FIG. 3 is a schematic view showing position relation between an
angle measuring instrument, an acceleration measuring meter and a hook in
the first embodiment;

[0036] FIG. 4 is a schematic view showing the comparison between a first
coordinate system and a second coordinate system in the first embodiment,
where coordinate axes of the first coordinate system are shown in solid
line and coordinate axes of the second coordinate system are shown in
dashed line; and

[0037]FIG. 5 is a schematic view showing a movement vectorial resultant
of the hook in the first embodiment.

DETAILED DESCRIPTION

[0038] The spirit of the present invention is to establish a first
coordinate system and a second coordinate system, wherein the second
coordinate system is concerned with the movement of a hook while the
first coordinate system is independent of the movement of the hook, thus
the change of attitude parameters of the hook may be reflected by the
change of a position relation between such two coordinate systems; then,
an angle relation between the coordinate axes of these two coordinate
systems is obtained by an angle measuring instrument, and an acceleration
of the hook in a predetermined direction of the second coordinate system
is obtained by an acceleration measuring meter, thus the accelerations of
the hook in the corresponding coordinate axes of the first coordinate
system are obtained according to the angle relation and the acceleration;
finally, the attitude parameters of the hook in the first coordinate
system are obtained according to the accelerations of the hook in the
coordinate axes of the first coordinate system, so as to provide a basis
for further controlling the movement of the hook.

[0039] The technical solutions of the present invention will be described
hereinafter by way of specific embodiments. The description in this
section of the specification is only illustrative and explanatory, and
should not be considered to limit the protection scope of the present
invention.

[0040] Referring to FIG. 1, a general structural schematic view of a truck
crane is shown. The truck crane in FIG. 1 includes a chassis 100, a
lifting arm 200 and a hook 400. The lifting arm 200 is installed on the
chassis 100 by a slewing mechanism, so as to can rotate about a vertical
axis in a horizontal plane relative to the chassis 100. A movable pulley
set is provided on the hook 400 and is connected with a fixed pulley set
on an upper part of the lifting arm 200 by a hanging wire rope 410. The
fixed pulley set is connected to a hoisting drum 300 of the crane by a
pulling wire rope 310. In hoisting operation, the hanging wire rope 410
is driven by the pulling wire rope 310 through the fixed pulley set, thus
the hook 400 is moved in a vertical direction and the hoisted goods is
moved in the vertical direction. The slewing mechanism between the
lifting arm 200 and the chassis 100 is rotated under the driving of a
suitable driving mechanism, which moves the lifting arm 200 relative to
the chassis 100, and causes the hook 400 and the hoisted goods to move in
the horizontal plane, thus the position of the goods is changed. The
rotation of the lifting arm 200 or an external force may causes the hook
400 hung on the upper part of the lifting arm 200 by the hanging wire
rope 410 to sway laterally, and the laterally swaying may affect the
efficiency of the hoisting operation of the crane.

[0041] Referring to FIG. 2, a structural block diagram of a hook attitude
detecting device according to a first embodiment of the present invention
is shown. The hook attitude detecting device according to the first
embodiment is used to measure the attitude parameters of the
above-mentioned hook of the crane, and includes an angle measuring
instrument 510, an acceleration measuring meter 520, a processor 530 and
an output device 540.

[0042] The processor 530 may establish two coordinate systems according to
the structural dimension of the crane, i.e. a first coordinate system O1
and a second coordinate system O2, with coordinate axes of the first
coordinate system O1 corresponding to coordinate axes of the second
coordinate system O2, respectively. The first coordinate system O1 and
the second coordinate system O2 are fixed relative to different devices,
respectively. Specifically, the second coordinate system O2 is fixed
relative to the hook 400, and the second coordinate system O1 is fixed
relative to an upper part of the lifting arm 200. Thus, the relative
position between these two coordinate systems may be changed when the
hook 400 sways or moves up and down relative to the lifting arm 200,
therefore, the change of the attitude parameters of the hook 400 may be
reflected on the change of the position relation between these two
coordinate systems, which provides a basis for determining the attitude
parameters of the hook 400. The first coordinate system O1 is not limited
to be fixed relative to the upper part of the lifting arm 200, and may be
also fixed relative to other parts of the crane in addition to the hook
400. If the crane is of other type of crane, such as a gantry crane, the
processor 530 may establish a coordinate system based on a predetermined
spatial position according to the actual requirement of the operation. As
long as the change of the movement and attitude parameters of the hook
400 can be reflected by the change of the position relation between the
first coordinate system O1 and the second coordinate system O2 during a
hoisting operation, the attitude parameters of the hook 400 may be
determined, thus the object of the present invention may be achieved.

[0043] In the first embodiment shown in FIG. 3, a schematic view showing
the comparison between the first coordinate system and the second
coordinate system is shown, where the coordinate axes of the first
coordinate system is shown in solid line while the coordinate axes of the
second coordinate system is shown in dashed line. In the embodiment, the
first coordinate system O1 and the second coordinate system O2 both are
three-dimensional rectangular coordinate systems. The first coordinate
system O1 includes three coordinate axes, which are a X1 axis, a Y1 axis
and a Z1 axis; and the second coordinate system O2 includes three
coordinate axes, which are a X2 axis, a Y2 axis and a Z2 axis; with the
X1 axis, the Y1 axis and the Z1 axis respectively corresponding to the X2
axis, the Y2 axis and the Z2 axis.

[0044] The angle measuring instrument 510 is adapted to obtain the angles
between the coordinate axes of the second coordinate system O2 and the
corresponding coordinate axes of the first coordinate system O1. In the
embodiment, the angle measuring instrument is a triaxial angle measuring
instrument which includes three measuring shafts. The axes of the three
measuring shafts are respectively parallel to the three coordinate axes
of the second coordinate system O2, that is to say, the angles between
the axes of the three measuring shaft and the three coordinate axes of
the second coordinate system O2 are all equal to zero degree. Thus, when
the second coordinate system O2 rotates relative to the first coordinate
system O1, the angles between the three coordinate axes of the second
coordinate system O2 and the corresponding coordinate axes of the first
coordinate system O1 may be obtained by respective measuring shafts. As
shown in FIG. 3, an angle "a" between the Z1 axis and the Z2 axis, an
angle "b" between the Y1 axis and the Y2 axis, an angle "c" between the
X1 axis and the X2 axis may be obtained by the angle measuring instrument
510. It is understood that the angle measuring instrument may also
include three angle sensors, each of which is utilized to measure the
angle between each pair of coordinate axes.

[0045] The acceleration measuring meter 520 is adapted to measure an
acceleration of the hook in a predetermined direction being at
predetermined angles relative to the coordinate axes of the second
coordinate system O2. In the embodiment, the acceleration measuring meter
520 is a triaxial acceleration measuring meter which includes three
measuring shafts. The axes of the three measuring shafts are respectively
parallel to the three coordinate axes of the second coordinate system O2,
that is to say, the angles between the axes of the three measuring shaft
and the three coordinate axes of the second coordinate system O2 are all
equal to zero degree. Thus, the acceleration in the direction of each
coordinate axis of the second coordinate system O2 may be obtained by the
acceleration measuring meter 520. As shown in FIG. 3, an acceleration
"αx2" along the X2 axis, an acceleration "αy2"
along the Y2 axis, an acceleration "αz2" along the Z2 axis may
be obtained by the acceleration measuring meter 520. It is understood
that the three measuring shafts of the triaxial acceleration measuring
meter may be at predetermined angles relative to the three coordinate
axes of the second coordinate system O2 respectively, rather than being
parallel to the three coordinate axes of the second coordinate system O2.
Thus, after the accelerations in the direction of the respective axes of
the three measuring shafts are obtained, the accelerations
αx2, αy2, αz2 of the hook 400 in the
direction of the coordinate axes of the second coordinate system O2 may
be obtained by calculating.

[0046] As shown in FIG. 4, a schematic view showing the position relation
between the angle measuring instrument, the acceleration measuring meter
and the hook is shown. In the embodiment, the angle measuring instrument
510 and the acceleration measuring meter 520 are fixed relative to the
hook 400, so that the date obtained by the angle measuring instrument 510
and the acceleration measuring meter 520 may directly relate to the
movement state of the hook 400. In addition, the angle measuring
instrument 510 and the acceleration measuring meter 520 may be fixed
relative to the hanging wire rope 410 of the hanging hook 400. The
attitude parameters of the hook 400 may be determined according to the
attitude parameters of the hanging wire rope 410, since the movement of
the hanging wire rope 410 may be synchronized with that of the hook 400
and there is a certain relation between the attitude parameters and the
movement state of the hanging wire rope 410 and the hook 400, thus the
object of the present invention may be achieved.

[0047] The processor 530 is also adapted to obtain the attitude parameters
of the hook 400 in the first coordinate system O1 according to the angles
obtained by the angle measuring instrument 510 and the accelerations
obtained by the acceleration measuring meter 520. The attitude parameters
may include a movement speed V, a movement direction and a position of
the hook 400 in the first coordinate system.

[0048] The output device 540 outputs the attitude parameters obtained by
the processor 530, so as to provide for the operator or the operating
system of the crane.

[0049] The specific method of obtaining the above-mentioned attitude
parameters will be described in following.

[0050] Firstly, the acceleration of the hook 400 in the direction of each
coordinate axis of the first coordinate system O1 is obtained; where, in
the first coordinate system O1, the acceleration in the direction of X1
axis is αx1=αx2×cosc, the acceleration in the
direction of Y1 axis is αy1=αy2×cosb, and the
acceleration in the direction of Z1 axis is
αz1=αz2×cosa. In this way, the acceleration
of the hook 400 in the direction of each coordinate axis of the first
coordinate system O1 may be obtained.

[0051] Secondly, the processor 530 performs a processing at a
predetermined period and obtains an instantaneous speed of the hook in
the direction of each coordinate axis of the first coordinate system O1
according to the obtained αx1, αy1, αz1
by the following equations:

Vx=V0x+∫αx1dt

Vy=V0y+∫αy1dt

Vz=V0z+∫αz1dt

[0052] where, Vx indicates an instantaneous speed of the hook 400 in
the direction of X1 axis, Vy indicates an instantaneous speed of the
hook 400 in the direction of Y1 axis, Vz indicates the instantaneous
speed of the hook in the direction of Z1 axis, and the instantaneous
speed is the real-time speed of the hook 400 obtained by the processor
530; V0x, V0y and V0z are respectively the initial speeds
in the directions of X1 axis, Y1 axis and Z1 axis, that is, the speeds
obtained by the processor 530 in a previous processing period, and "dt"
indicates the processing period of the processor 530. Thus, in the first
coordinate system O1, the instantaneous speed in the direction of each
coordinate axis of the first coordinate system O1 may be obtain according
to a discrete function of the acceleration associated with the time. The
hook attitude detection device may start operating when the hoisting
operation of the crane is performed, and preset the values of the
V0x, V0y and V0z according to the state on the beginning
of the hoisting so as to enable the processor 530 to obtain the
instantaneous speed in the direction of each coordinate axis of the first
coordinate system O1 according to the angles obtained by the angle
measuring instrument 510 and the accelerations obtained by the
acceleration measuring meter 520. The instantaneous speed may reflect the
real-time movement state of the hook 400, and the real-time attitude
parameters of the hook 400 may be further determined according to the
instantaneous speed.

[0053] As shown in FIG. 5, a schematic view showing the movement vectorial
resultant of the hook is shown. The instantaneous speed V of the hook 400
in the first coordinate system O1 may be obtained according to the
relation between Vx, Vy and Vz, and this instantaneous
speed is the overall speed of the hook 400, where

V= {square root over (Vx2+VY2+VZ2)}.

[0054] Then, the movement position of the hook 400 may be obtained and
determined according to the distance between the hook 400 and the
predetermined position. Since a movement track of the hook 400 is
nonlinear, in order to accurately obtain the distance between the hook
400 and the predetermined position, the instantaneous displacement of the
hook 400 in the direction of each coordinate axis of the first coordinate
system O1 relative to the predetermined position may be obtained at
first, where:

[0055] the instantaneous displacement in the direction of the X1 axis is
Sx=S0x+∫∫αx1dt,

[0056] the instantaneous displacement in the direction of the Y1 axis is
SY=S0Y+∫∫αx1dt, and

[0057] the instantaneous displacement in the direction of the Z1 axis is
SZ=S0Z+∫∫αz1dt.

[0058] In the above formulas, S0x, S0y and S0z are
respectively the initial distances in the direction of the X1 axis, the
Y1 axis and the Z1 axis between the hook 400 and the predetermined
position, that is, the instantaneous displacements obtained by the
processor 530 in a previous processing period; "dt" indicates the
processing period of the processor 530. Thus, in the first coordinate
system O1, the instantaneous displacement of the hook 400 in the
direction of each coordinate axis of the first coordinate system O1 may
be obtained according to a discrete function of the acceleration
associated with the time, and the instantaneous distance in the direction
of each coordinate axis between the hook 400 and the predetermined
position is obtained. Taking the stationary position of the hook as a
reference, the offset amount of the hook 400 in the direction of each
coordinate axis may be determined, so as to determine the swaying
distance and amplitude. Further, the instantaneous displacement S of the
hook 400, which is overall displacement of the hook 400, in the first
coordinate system O1 may be obtained according to SX, SY,
SZ, so as to determine the instantaneous distance between the hook
400 and the predetermined position, that is:

S= {square root over (Sx2+SY2+SZ2)}.

[0059] Similarly, taking the stationary position of the hook as a
reference, the position and the swaying amplitude of the hook 400 may be
determined.

[0060] According to the above-mentioned attitude parameters obtained by
the processor 530, the operator may accurately know information of the
hook 400 such as the position, the instantaneous speed and the swaying
amplitude to determine the movement state of the hook 400, so as to can
take more suitable hook-stabilizing measures to reduce the time required
for the hoisting operation and to improve the efficiency of the hoisting
operation.

[0061] In actual hoisting operation, the above-mentioned object of the
invention may achieved by two two-dimensional coordinate systems. The
first coordinate system O1 and the second coordinate system O2 are not
limited to rectangular coordinate systems, and also may be polar
coordinate systems or other coordinate systems. In the case that the
first coordinate system O1 and the second coordinate system O2 both
include one coordinate axis or two coordinate axes, the angle measuring
instrument 510 may include one measuring shaft or two measuring shafts,
and the axis of each measuring shaft is parallel to or is at a
predetermined angle relative to a coordinate axis of the second
coordinate system O2. Similarly, the angle between the corresponding
coordinate axes of the two coordinate systems may be obtained in the
above-mentioned manner, so as to further obtain the accelerations of the
hook 400 in the direction of the corresponding coordinate axis of the
first coordinate system O1 according to the angle and the acceleration
obtained by the acceleration measuring meter 520, and to further obtain
the attitude parameters of the hook 400.

[0062] Similarly, in the case that the first coordinate system O1 and the
second coordinate system O2 are other types of coordinate systems, the
acceleration measuring meter 520 may also include one measuring shaft or
two measuring shafts, and the axis of each measuring shaft is parallel to
or is at a predetermined angle relative to a coordinate axis of the
second coordinate system O2, and the acceleration of the hook 400 in the
direction of the corresponding coordinate axis of the second coordinate
system O2 can be obtained likewise in the above-mentioned manner, so as
to achieve the object of the present invention. In order to obtain the
acceleration of the hook 400 more accurately, the preferred technical
solution is that the acceleration measuring meter has the function of
measuring the acceleration in three dimensional directions, so as to more
accurately obtain the components of acceleration in the direction of the
predetermined coordinate axis.

[0063] In order to allow the operator to more directly determine the
attitude of the hook 400, the output device 540 may be an indicating
light which makes a predetermined indication when the predetermined
attitude parameters of the hook 400 reach to a predetermined value; or
may be a display device by which the attitude parameters of the hook is
displayed in a suitable way, for example, the position and the movement
track of the hook 400 may be displayed on the display device in the form
of a schematic diagram, so that the operator may know the position of the
hook 400 according to the schematic drawing displayed on the display
device and determine the swaying amplitude of the hook 400. In addition,
the processor 530 may preset threshold values of the parameters according
to an actual requirements of the hoisting operation and the actual
conditions of the hook 400, and compare the obtained predetermined
attitude parameters of the hook 400 with the preset threshold values of
the parameters, so as to determine whether the movement state of the hook
400 affects the normal hoisting operation or not, and then to perform a
predetermined processing according to the comparison result. For example,
it is possible to preset a speed threshold value of the hook 400, so that
a corresponding processing is performed when the speed of the hook 400 is
excessively high. It is also possible to set a swaying amplitude
threshold value, so that a corresponding predetermined processing is
performed when the position of the hook 400 is out of the swaying
amplitude threshold value. The predetermined processing may be to give a
suitable alarm, generate a suitable signal or the like, or may be to
force the crane to stop operating by a control system of the crane in the
case of occurring large security risks.

[0064] Since the hook attitude detecting device according to the present
invention has the above technical effects, the crane including the
above-mentioned hook attitude detecting device also has corresponding
technical effects. In order to facilitate the information communication
and to facilitate for the operator knowing the condition of the hook 400,
the processor 530 and the angle measuring instrument 510 may be both
fixed to the hook 400 or the hanging wire rope 410, and the output device
540 may be installed in a control cab, and may be in a wireless
communication with the processor 530.

[0065] The above-mentioned description is just the preferred embodiments
of the present invention. It should be noted that some improvements and
modifications may be made by the skilled in the art without departing
from the principle of the present invention, for example, the angle
measuring instrument 510 may be an angle sensor, a magnetometer, a
gyroscope, etc., and the processor 530 may also include a filtering
device, an AD converter, etc. These improvements and modifications should
be deemed to fall into the scope of protection of the present invention.